Projector



" Sept. 16, 1941.

D. CRITOPH ETAL 2,256,424

PROJECTOR Filed Sept. 9, 1938 5 Sheets-Sheet l 5)? M 94 4.4% @INVENTORS ATTORN EY Sept. 16, 1941. b. CRITOPH ETALY PROJECTOR Filed Sept. 9. 1938 5 Sheets-Sheet 2 ..;m1mmmm 7? INVENTQRS Wm f Sept. 16, 1941. D. CRITOPH ETAL PROJECTOR Filed Sept. 9. 1938 5 Sheets-Sheet 3 m 7%. as

ATTORNEY se g. 16, 1941.

D. l. CRITOPH ETAL PROJECTOR Filed Sept. 9, 1938 lllmlllll 5 Sheets-Sheet 4 INVENTORS ATTORN EY p .16,1941. D. CRITOPH Em. 2 256,424

PROJECTOR Filed Sept. 9, 1938 5 Sheets-Sheet 5 ATTORNEY Patented Sept. 16, .1941

PROJECTOR David I. Critoph and Walter H. Popp, Bufialo,

N. Y., assignors Bulfalo, N. Y.,

to Spencer Lens Company, a corporation of New York Application September 9, 1938, Serial No. 229,160 4 Claims. (01. 88-24) This invention relates to a projector, andmore particularly to an opaque projector for projecting either an enlarged or a reduced image of an aeronautical photograph or a map upon a sheet of drawing paper, so that the draftsman is enabled to trace upon said ever features of the be desired.

The principal object of the invention is to provide a reliable and yet inexpensive projector in which photographs or maps of different size or character may be quickly placed in approximately correct position for projection and thereafter accurately oriented with respect to whatever reference points may have been previously located on the drawing paper or on the projector itself. Numerous other objects of the invention and practical solutions thereof are described in the following specification and illustrated in the attached drawings, wherein:

Fig. 1 is a diminutive front elevation of our improved projector showing the same attached to such a typical form of drafting table as it is adapted to be used with.

Fig. 2 is a fragmentary front elevation of one form of framing device used with the projector.

Fig. 3 is a fragmentary vertical section through said framing device taken on line 33 of Fig. 2.

drawing paper whatphotograph or map that may Fig. 3a is an enlarged fragmentary detail of said framing device taken on line '3-3 Fig. 2. Fig. 4 is an enlarged fragmentary front elevation of said framing device showing the same in swiveled position.

Fig. 5 is a fragmentary front elevation of an attachment for the projector constituting a modifled form of framing device.

Fig. 6 is a fragmentary vertical longitudinal section thereof, taken on line 66 of Fig. 5.

Fig. 7 is an enlarged fragmentary vertical section thereof, taken on line 1-1 of Fig. 5.

Fig. 8 is a fragmentary front elevation of still another attachment for the projector constituting another modified form of framing device.

Fig. 9 is a fragmentary vertical sectionthereof, I

taken on line 99 of Fig. 8.

Fig. 10 is a fragmentary front elevation of another attachment for the projector constituting another modified form of framing device.

Fig. 11 is an enlarged fragmentary horizontal section thereof, taken on line Ill I, Fig. 10.

Similar characters of reference indicate like parts throughout the several figures of the drawings.

It is to be understood that the present inven-' tion is not confined to the constructions shown on the accompanying drawings, but that the latter are merely illustrative of the invention and that the scope of the invention is scope of the appended claims.

Figs. 1-4

' In its general organization, the present invention consists of a rectangular box or casing 20 in which are arranged a pair of electric light bulbs 2| which illuminate the vertical photograph or other representation 22 which is to be projected. The image of this representation 22 is reflected in the usual and well known manner through a suitable objective 23 and upon the upper surface of the drawing paper 24 which is placed upon the upper surface of the drafting table 25. Said casing 20 is vertically adjustable relatively to said table 25 by being mounted on a pair of brackets 26, which are vertically slideable upon a pair of upright pillars 21. The latter are connected together at their upper ends by a hollow cap 28 and connected together at their lower ends by a base plate 29 which is supported upon the floor 30 by ,two adjustable rear feet 3i and an adjustable front foot 32. To prevent the table 25 from shifting laterally relatively to the projector, the horizontal topv cured to a pair of slide clamps 34 by means of clamp screws 35. The vertical position ofsaid slide clamps 34 is rendered vertically adjustable on the pillars 21 by means of suitable set screws 36.

Vertical adjustment of the casing 20 is effected by a hand wheel 31 which is joum'aled in a suitable member (not shown) which is clamped to the lower flange 38 of the table 25 and is connected through a flexible shaft 39 with a worm 40. Thelatter is adapted to drive a worm wheel ll which is connected to a pair of cable drums 42 and 42a. Wound upon these drums in reverse directions is a. hoisting cable 43 and a lowering cable 43a. These cables are suitably connected with the casing 20 through the intermediary of suitable pulleys (not shown) in the hollow cap 28 in the usual and well known manner. The weight of said casing 20 and the parts which move therewith are suitably counter-balanced in any suitable manner such as, for instance, by means of the cables 45 and 46 which are connected with suitable counter-weights arranged in the hollow pillars 21.

Focusing of the objective 23 relative to the casing 20 may be effected in'any suitable manner not deemed necessary to be. illustratedin the present patent. Light passing from the casing only limited by the v 33 of the table is se- 29 down through the objective 29 is prevented from being interfered with by the usual form of tapered accordion type of bellows 41.

Formed in the front vertical wall 49 of the casing 20 is a circular aperture 49. Arranged against the inner face of said vertical front wall 49 is a swivel head 50 which is of disc shape and has a diameter somewhat larger than the diameter of the aforesaid aperture 49. This swivel head is rotatably secured in position on said front wall 48 by three L shaped cleats 5| which are secured to said front wall 48 of the casing 29 by cap screws 52 or otherwise. Formed in the lower part of said swivel head 50 is a short radial slot 53. Arranged behind the rear face of said swivel head 59 and below the bottom face of the bottom wall 44 of the casing 29 is a thrust bar which is preferably in the form of a rack 54. The latter is arranged in a suitable guide block 55 which is fastened by bolts 49 or otherwise secured to the bottom face of the bottom wall 44 of the casing 20. This arrangement permits said rack to move longitudinally and horizontally in the one or other direction against the bottom face of the bottom wall 44 of the casing 20. Secured to said rack 54 is a shouldered cap screw 56 whose shank is received within aforesaid slot 53 of the swivel head 59. Actuation of said rack in the one or other direction is effected by pinion 51 whose hub is secured by a pin 59 or otherwise to a vertical swivel shaft 59. The latter is suitably journalled at 59c below the pinion 51 in aforesaid guide block 55 and is journaled above said pinion in a bearing block 50 bolted by bolts 49 to the bottom wall 44 of the casing. Secured to the lower end of said swivel shaft 59 is an actuating knob 6| whereby the operator is enabled to conveniently turn said swivel shaft 59 in the one or other direction and to thereby move the rack 54 in the one or other direction and to thereby swing, when desired, the swivel head 59 to some such position as that shown in Fig. The main advantage of this feature of the invention is that circular movement of the swivel head 50 is effected by means of a straight rack 54 and its associated parts rather than by some relatively expensive circular gear construction.

Formed in the central part of the swivel head 59 is a rectangular aperture 92. Arranged against the front face of said swivel head 59 in register with said aperture 92, and having dimensions somewhat larger than the same, is a transparent plate 63. The latter rests upon a pair of L shaped ledges 94 and is held in position by a pair of side cleats 65 which are secured to the front face of the swivel head by screws 59 and, as best shown in Figs 11 and 2, and are'bent forwardly and inwardly to engage the beveled side faces 91 of the transparent plate 63.

Secured by detachable thumb screws 69 to the front face of the swivel head 59 are a plurality of clips 19 whose inner ends are bent forwardly and then inwardly and are welded to the front face of a rectangular, open-faced frame H. The latter is of L shaped cross section as best shown in Fig. 3a, and has a central square aperture 12 which is adapted to register with the rectangular aperture 92 of the swivel head 50. This frame 1| does not bear directly against the front face of the transparent plate 93 but has a suitable felt gasket 13 interposed therebetween as best shown in Fig. 3a.

At the upper part of rectangular square frame H is welded a pair of hinges 14 whose upper leaves 15 are welded to said rectangular frame H and whole lower leaves I9 are welded to the upper edge of a rectangular primary holding plate 11. The photograph or other representation 22 being projected is adapted to be disposed between the front face of the transparent plate 93 and the rear face of said primary holding plate 11. A suitable resilient gasket 99 is pref-'- erably cemented to the rear face of said primary holding plate ll so as to effect a soft uniform pressure of said primary holding plate upon the photograph or other representation 22. 'Said primary holding plate 11 is adapted to be resiliently urged toward the transparent plate 63 by means of a suitable spring 92 whose lower arm bears against the upper outer face of the primary holding plate 11 and whose upper end is,

suitably dually curled to provide the required resilience and is secured by cap screws 83 to the uppermost of the clips 10. Excessive movement of said upper holding plate 11 toward the transparent plate 63 is prevented by a pair of limiting lugs 94 whose inner ends are welded or otherwise suitably secured to the front face of said' primary holding plate 11 and whose outer ends project beyond the outer edges of said primary holding plate and are adapted to engage the front face of the frame 1|. This prevents the momentum of the primary holding plate 11 from breaking the transparent plate 93 in the event that said primary holding plate is allowed to snap down too suddenly to its closed position which is shown in the drawings.

Arranged at the lower end of the primary holding plate 11 is a pair of hinges 85 whose upper leaves 99 are welded or otherwise secured to the lower edge of said primary. holding plates I1, and whose lower leaves 91 are welded or otherwise secured to the upper edge of a secondary holding plate 99. The latter is provided at its side edges with a pair of outwardly extending, limiting lugs 99 which prevent fracture of the transparent plate 63 in the same manner as afore-described limiting lugs 94. Arranged at the lower central part of the secondary holding plate 99 is a latch 9|. This latch consists of a slide bar 92 which is slideably arranged in a frame 93 which is secured to the lower holding plate 99 by means such as the rivets 94. Projecting laterally downwardly from said slide bar 92 isa pair of fingers 95 which are adapted to slide under and be engaged by a pair of tongues 99 whose left ends are secured by welding or otherwise to the front, vertical, outer face of the rectangular frame II. By opening the latch 9| and the secondary holding plate 99 the operator is enabled to push the representation 22 to whateyer position may be desired, said representation being in the meantime resiliently held in place by the-upper or primary holding plate 11 and its spring 92. When the representation 22 is to be either put into position or taken out of the projector, both the secondary holding plate 99 and the primary holding plate 11, are opened up by being swung about the upper hinges 14 as a pivot.

With this construction the standard sized photograph or other representation being projected may be placed in approximately correct alignment by pushing it against the transparent plate 93 within the inner boundaries of the rectangular gasket 13 of the frame H. The draftsman then drops the primary holding plate 11 into position and this by means of spring 92 resiliently holds the representation in place while he holds the secondary holding plate 99 open and is thereby enabled to shift the representation 22 until it is ing paper 24 are being used. The secondary holding plate 88 is then latchedwith its latch 8|. The draftsman then traces upon the drawing paper 24 whatever features of the photograph are desired.

Figs. 5-7

If the thumb screws 68 afore-described be re moved, the frame 1I together with its primary and secondary holding plates 11 and 88 and its other appurtenances, may be entirely removed.

This enables the same to be replaced by the framthese thumb screws I are identical with the thumb screws 68 of Figs. 1-4 but difi'erent num bers have been applied to these screws in Figs -7 so as to avoid any possibility of confusion'in reading the drawings. Secured to the central upper face of said supporting bar 98 is a pair of bearings I02 in which are journaled the lower ends of a pair of legs I03 which, together with their integral cross tie member I04, constitute a pressure arm I05. The upper end of the latter is pivoted at I06 to the central part of the primary holding plate I01. The latter has a smooth, unobstructed, rear face, as best shown in Fig. 6, to which is preferably applied a rectangular shaped piece of felt or gasket I08. To render this primary holding plate I01 sufliciently stifi it is preferably provided on its lateral edges with a pair of flanges I I0 and at its lower edge with a stiffening flange III.

Arranged atthe upper part of the primary holding plate I01 is a pair of hinges II2 whose lower leaves II3 are welded to the upper edge of said primary holding plate I01 and whose upper leaves II4 are welded to the lower edge of a secondary holding plate II5. Said secondary holding plate is resiliently urged to rotate relatively to said primary holding plate I01 by a spring II6 whose U shaped upper arm engages the rear face of the secondary holding plate III and whose lower coiled end is secured by cap screws II1 to the primary holding plate I 01. To enable the secondary holding plate I'I5 to be conveniently grasped, it is preferably provided with a bent,

sheet metal handle II 8 and the primary holding plate is preferably similarly provided with a bent, sheet metal handle I20.

For purposes of stiffening, the secondary holding plate H5 is preferably provided integrally at its upper edge with a horizontal stiffening flange I2I and at its side edges with a pair of vertical side stiffening flanges I22. Secured by rivets I23 or otherwise to each of said side stiffening flanges I22 is a pair of L shaped limiting lugs I24 which project laterally outward beyond the outer faces of said side stiffening flanges I22. The rear,

outer faces of said limiting lugs I24 are adapted to come in contact with the front, outer ends of a pair of limiting bars I25 which are secured at their lower ends by rivets I26 to the side flanges H0 of the primary holding plate I01. This construction prevents a careless operator from allowing the secondary holding plate H5 to snap so violently back as to break the transparent plate 63.

, block Figs. 8-9 This construction is similar to Figs. 5-6 in that it permits of employing representations of large sized representation such as the map I21 indicated by dotted lines in Fig. 9, but it is different in that the thrust arm I28 is pivoted to a bearing block I30 on the swivel head 50 instead of being pivoted to the casing 20. This bearing block I 30 is secured by cap screws I3I or otherwise to the lower front face of the said swivel ,head 50 and has journaled thereon the lower cross bar I32 of said thrust arm I28. This pivotal connection between the thrust arm I28 and the pivot block I30 is preferably of a detachable nature by the employment, for instance, of a pair of bearing clips I33 secured by cap screws I34 to said bearing block. The central part of the cross bar I32 of thrust arm I28 is curved and is pivotally connected at I35 with the lower end of a tension spring I36. This spring is a past-dead-center spring in that when in the position of Figs. 8 and 9 it resiliently urges the primary holding plate I31 toward the transparent plate 63, whereas, when said primary holding plate I31 is swung clear down to its fully opened position, the lower end I35 of said tension spring I36 swings past the axis of the cross bar I32 of the thrust arm I28 and is thereby enabled to resiliently hold the primary holding plate I31 in its open position. When said primary holding plate I31 is in its completely open position, it is prevented from moving any further by reason of a pair of ledges I38 which are integrally formed with the bearing I30 and project laterally and horizontally outwardly therefrom and are adapted to engage the lower ends of the thrust arm I28. Excessive movement of the primary holding plate I31 relatively to the thrust arm I28 in a counter-clockwise direction (as seen in Fig. 9) is prevented by a pair of limiting fingers I40 which are formed by bending upwardly and outwardly the upper, outer ends of the thrust arm I28.

Figs. 1 0-11 In commercial practice it frequently happensthat a projector has to be used with two different sizes of representations. When these two sizes are of standard size the construction shown of thumb screws I42, the latter engaging clips I43 which are welded at their inner ends to said frame I. Arranged at the upper end of said frame is a pair of hinges I44 whose upper leaves I45 are welded to said frame I and whose lower leaves I46 are welded to an open-faced, primary holding plate I41. The latter has welded or otherwise secured to its lateral edges a, pair of limiting bars I46 which stiffen said primary holding plate and,- in addition, project horizontally, downward beyond its lower edge and act as limiting lugs by engaging with the front,

lower face of the frame I. Said primary holding plate I41 is adapted to beheld in its closed position by a suitable latch I50 which is similar I nected to the upper part of the primary holding plate'I41 by'means of hinges I53. The lower movement of the part of said secondary holding plate I52 is provided with a suitable latch I54 whereby it may be firmly held in position with reference to said primary holding plate I41. Any fracture of the transparent plate 63 as a consequence of a too violent closing of the secondary holding plate I52 is prevented by a pair of limiting lugs I55 which are welded to the lower, front face of said secondary holding plate I52 and are adapted to engage with the lower iront face of the primary holding plate I41. A suitable gasket I56 is cemented to the inner face of the inner or secondary holding plate I52 (as best shown in Fig. 11). Another gasket I51 is cemented to the inner face of the primary holding plate I41 and a similar gasket I58 is cemented to the inner face of the frame I.

With this construction if the operator of the projector desires to project small sized representations, he opens the latch I54 and swings the secondary holding plate I52 about its hinges I53. These small representations are then approximately aligned by the felt gasket I51 of the primary holding plate I41 and the representation then shifted until it'is in exact alignment. If, on the other hand, he is dealing with large sized representations, he does not disturb said latch I54 but, instead, opens the latch I50 and moves the primary holding plate I41, together with the secondary holding plate I52 and its appurtenances, about the hinges I44, thereby exposing a larger area of the transparent plate, so that larger representations can be placed in position, and approximately aligned by the gasket I58 of the frame I.

It is to be understood that the projector as a whole is not disturbed when using the framing devices of .Figs. 1-4, Figs. 5-7, Figs. 8-9, and Figs. 10-11, the desired framing device being applied to the swivel plate 50 or the channel bars IOI of the projector as the case may be. In other words each of these framing devices is an optional accessory of the projector and may be replaced by any one of the others.

We claim:

1. A projector including a illumination and an optical system, an opening in one wall of said casing, a holding plate in said opening, a door in said holding plate for insertion and removal of material to be projected in said projector, and adapted to retain said material in position for projecting the same, said holding plate having a portion overlapping an' edge of one wall of said casing, a slot in said overlapping portion, a guide member secured to said casing adjacent said overlapping portion of said holding plate, a thrust bar slidably supported on said guide member, a pinion on said guide member for moving said thrust bar, and a member secured to said thrust bar and extending into the slot in the said overlapping portion of the holding plate, whereby thrust bar by rotation of the casing, a source of pinion will simultaneously pivot said holding P 2. A projector including a casing, a source of illumination and an optical system, an opening in one wall of said casing, a holding plate in said opening, a door in said holding plate for the insertion and removal of material to be projected, and adapted to retain said material in position for projecting the same, said holding plate having a portion overlapping an edge of one wall of said casing, a slot in said overlapping portion, a guide member secured to said casing adjacent said overlapping portion of said holding plate, a thrust bar slidably supported on said guide member, a pinion on said guide member for moving said thrust bar, and a member secured to said thrust bar adjacent the center thereof and extending into the slot in the said overlapping portion of the holding plate, whereby movement of the thrust bar will simultaneously pivot said holding plate.

3. A projector including a casing, a source of illumination and an optical system, an opening in one wall of said casing, a holding plate in alignment with said opening, a door in said holding plate for insertion and removal of material to be projected by said projector, and adapted to retain said material in position for projecting the same, a guide member carried by the casing, a thrust bar slidably supported on said guide'member, said holding plate having a portion overlying a portion of said thrust bar, one of said portions having a guideway therein and the other a member extending in said guideway, and means interconnected with said thrust bar whereby movement of said means will cause said thrust bar to move in a direction longitudinally-of the guide member and will simul-- taneously rotate said holding plate.

4. A projector including a casing, a source of illumination and an optical system, an opening in a side wall of said casing, a holding plate member rotatably supported in alignment with said opening, a door in said holding plate member for insertion and removal of material to be projected by said projector, and adapted to retain said material in position for projecting the same, a longitudinally adjustable member supported by said casing, said holding plate member and said longitudinally adjustable member being positioned in adjacent relation with each other with one of said members having a guideway therein and the other member having a projection portion extending in said guideway, and means interconnected with said longitudinally adjustable member whereby movement of said means will cause said adjustable member to move in a longitudinal direction and simultaneously rotate said holding plate member.

DAVID I. CRITOPH.

WALTER H. POPP. 

